Reorganize the config reference

[ptgott]

Closes #11253

This change breaks up the config reference by moving each Teleport service's configuration settings into a separate YAML snippet, and organizing each YAML snippet into a TabItem within a Tabs with dropdownView enabled. When Teleport Enterprise Cloud doesn't support a service, this change adds a Notice with a message about Teleport Enterprise Cloud in the relevant TabItem.

I thought this approach would be cleaner than alternatives:

• Including an H2 for each service: With this approach, the configuration reference would be even longer than it is now. With the approach I'm proposing, readers would navigate to "Reference configurations", then choose a service from a dropdown menu: much less scrolling for slightly more clicking.

• Including another set of TabItems for Teleport editions: I thought about adding a Tabs with a dropdown option for each Teleport edition and a horizontal TabItem for each service, but this would require horizontal scrolling and doesn't scale very well.

• Including horizontal tabs for each Teleport edition, with an inner dropdown menu for each Teleport service: There is currently no way to do this without multiple Tabs components, which gets messy quickly.

Note that this change does not attempt to copy-edit comments/example values within the configuration snippets. The scope of this change is limited only to reorganization.

[alexfornuto]

This could go out as is, but I left some comments for possible improvements.
Additionally, I noticed that the indenting is not consistent between these example files, some use 2 spaces and others use 4.

[zmb3]

I'm not sure this is in line with the goals set out in #15061 and gravitational/docs#93

I'd much prefer all the text be on one page where I can quickly cmd+f and search for it, rather than having to click through tabs.

Thoughts?

[alexfornuto]

searching through one long page works when you know what you're looking for. For those looking to learn about configs, separating them makes it easier to parse.

Additionally this page, as it is, is too big for our crawler:

Record extracted is too big (108KB), the maximum is 97.65625KB

And it's only gonna get bigger as we add product features.

So: What about having instance-wide settings on this page, and sub-pages for each service type? That way each page could still be easily searchable when you know what service type it belongs to, and also easier for someone to learn from going top-to-bottom?

[ptgott]

@alexfornuto I pushed a change to split up the config reference using headings per Zac's feedback. I didn't want to split this into sub-pages, since the docs already has pages devoted to the configuration sections for specific Teleport services, and it would be pretty confusing to have, say, the Application Service config reference in the "Application Access" section (https://goteleport.com/docs/application-access/reference/) as well as in the Reference section.

[public-teleport-github-review-bot]

@ptgott See the table below for backport results.

Branch	Result
branch/v10	Failed
branch/v11	Failed
branch/v12	Create PR